Figure 3. Assessment of antioxidative defence.

(A) Degradation of H₂O₂. Cells pre-exposed for 12 h to 100 μM Zn (or not) showed the same H₂O₂ degradation kinetics. A representative experiment is shown. (B) Measurement of total reduced thiols. Compared with control cells, the amount of total reduced thiols did not change following exposure of cells to 100 μM Zn for 12 h. H₂O₂-induced oxidative stress (a single bolus dose of initially 100 μM for 30 min) decreased reduced thiols by approx. 50%. This decrease was slightly (but not significantly) less in cells pre-exposed to 100 μM Zn for 12 h. Results are expressed as means±S.D. for four experiments. Comparisons were made against untreated controls.